Knoxfield

The Masterplan provides for a signalized intersection along Scoresby Road at Applegum Crescent, and a proposed second entry/exit point along Burwood Highway, adjacent to the mixed-use precinct area. This proposed second entry/exit point has been included in response to community feedback relating to traffic congestion and access concerns.

While the second entry/exit point is yet to be approved, Development Victoria will continue to advocate for its inclusion with Council and VicRoads, the statutory road management authority.

Development Victoria originally looked at delivering the housing development around the dam as this would provide the best protection to the dam’s existing habitat. Unfortunately, once the dam was assessed by expert hydrologists, it was found that:

• It was structurally unsound with leaks and cracks in the dam wall detected. 

• The banks are too steep. Waterbodies in residential areas are required to have gently sloping banks so if someone was to fall in, they could safely stand and make their way out. This is not the case with the Knoxfield dam. If someone was to fall in, it could be a potentially very dangerous.

• The dam does not meet the stormwater management requirements for the site. 

The new wetland will provide:

• an enhanced habitat for water birds, including the endangered Blue-billed Duck, resulting in a better overall environmental outcome for the area.
• an improvement to the water quality and available breeding habitat for local species through targeted planting which is currently absent at the existing dam. This includes planting dense vegetation and reed beds with the Blue-billed Duck in mind.
• a range of settling, sedimentation and water retention ponds to treat stormwater, mitigate flooding and protect Blind Creek.
• an area that is safe and not at risk of collapse which is a high likelihood for the existing dam.
• a safe public pathway through the wetland to Blind Creek which will create a new recreational link to the area that is safe for people and wildlife.

Due to its age and original construction the dam is structurally unsound, with leaks and cracks in the dam wall detected. While this can be repaired in the short term, fixing the structural issues long term would require the dam to be drained which would significantly impact the dam’s existing habitat, including the loss of Blue-billed Duck nesting habitat.

The repairs to the structural problems with the dam will have to occur regardless of the future use of the site meaning the loss of habitat is ultimately unavoidable.

Given there is no future scenario where the dam habitat can be protected, Development Victoria designed a new wetland that provides better nesting habitat for water birds including the Blue-billed Duck and meets the safety and flood and stormwater management requirements for the site.

The existing dam has a small area which is 4 metres deep however the majority of the dam averages around 1.5-2 meters in depth, including steep banks which are very unsafe for the local community if anyone were to fall in.

The proposed new wetland design is larger than the space of the existing dam and will consist of three key waterbodies with a water depth up to two metres. The largest of these is being specifically designed for the Blue-billed Duck and meets Melbourne Water’s requirements for wetlands depth. It will also be made safe for the public with battered edges which will provide a gentle slope into the dam.

Construction of the new wetland will occur in a staged manner, providing continual access to a waterbody for wildlife currently using the existing dam. The current dam will remain in place for approximately 12 months after the new wetland is built to ensure that the planting in the new wetlands is well established.

After the first phase of the improved wetland is established, the existing dam will be partially filled and redeveloped as part of an overall water retardation, filtration and habitat system. The proposed staged construction plan for the wetland can be viewed here. 

The wetland will be delivered in stages to ensure there is always a significant body of water on site for the Blue-billed Duck and other species.

During the staged construction, we will continue to monitor the behaviour of the Blue-billed Duck and other species. Decommissioning of the existing dam will commence after we have seen sufficient establishment to support the existing water bird species. This will be guided by our expert ecologist. We will take all steps to ensure there is always a significant body of water on site for the Blue-billed Duck and other species.

No. When Development Victoria first acquired the site, we looked at designing the housing development around the dam to provide the best protection to the dams existing habitat and be the most cost effective.

However, due to the structural issues with the dam, we had to design a new wetland that meets safety criteria for the slopes of the dam’s banks, meets the design requirements for flood and stormwater management and provides better nesting habitat for water birds including the Blue-billed Duck.

Feedback received in 2019 was compiled and considered along with a range of technical and environmental investigations to develop a draft Masterplan for the site. The draft Masterplan will be used to guide how the new neighbourhood will be developed in the future.

Development Victoria has also met with key community groups over a number of years to listen to their views and desires to maintain the existing dam on the site. Throughout this period, we have endeavoured to explain the structural issues with the dam and the limitations this placed on saving the Blue-billed Duck habitat.

We understand the importance of this site to the community which has become home to a range of vulnerable species. It is our continued commitment to work with the local community on the final design of the wetland and public areas so it can meet the community’s desires for a healthy, vibrant wetland that can support a range of wildlife, including the Blue-billed Duck.